Massive initial states seem not to work - four mom conservation fails

[Frank Krauss]

Run card is attached.

[Frank Krauss]

Two types of error messages:

1. Remnant_Base::AdjustKinematics(): Parton (0xab05b60) has non-positive energy (-nan,-nan,-nan,-nan)

2. Blob_List::FourMomentumConservation(): (0x9e1f744) Four Momentum is not conserved. p_{in} = (3500,0,0,-3500) vs. p_{out} = (3498.02,-1.32457,-0.562421,-3498.02).

While 1. is kind of rare (3 incidents in 10k events), 2. happens in about 1% of events.

I suspect I should add a masscut on the three outgoing objects, but I thought this was implicitly already done.

[Frank Siegert]

I can reproduce these, they seem to come from the beam remnants, since BEAM_REMNANTS=Off gets rid of them.

Aside: The syntax in your scale definition is wrong, it has to be MPerp2(...).

Here is a minimal Run.dat to reproduce this:

(run){
  EVENTS 1000000;

  EVENT_GENERATION_MODE Weighted;
  MASSIVE[5] = 1
  FRAGMENTATION=Off

  BEAM_1  2212; BEAM_ENERGY_1 3500;
  BEAM_2  2212; BEAM_ENERGY_2 3500;
}(run)

(processes){
  Process 93 5  -> 13 -13 5
  Order_EW 2;
  End process;
}(processes)

(selector){
  PT     5      5 E_CMS;
  PT    -5      5 E_CMS;
  PT    13      5 E_CMS;
  Mass  13 -13 15 E_CMS;
}(selector)

[Stefan Hoeche]

This issue is solved with r17318. A problem in the CSS remains, which leads to 4-momentum violations and occurs every ~10000 events.

[Stefan Hoeche]

Solved in r17321.

[Stefan Hoeche]

Milestone rel-1.3.0 deleted